Antibodies Flashcards
What are monoclonal antibodies?
-isolated antibodies
Why is the structure of an antibody called quaternary?
It contains 4 (more than 1) polypeptide chains
What two chain types make up an antibody?
1) the heavy (long) chain
2) the light (short) chain
What holds the antibody together?
Disulphide bridges
Where and how is the antigen-antibody complex formed?
At the antigen binding sites which are specific and complimentary to the tertiary shape of an antigen
Which part of the chain is variable/constant?
-The receptor binding site is constant as it doesn’t change between antibodies
-The antigen binding sites are variable as they’re different in different antibodies
How is the variable region variable?
The DNA sequence varies, meaning the mRNA sequence is varied, resulting in a different amino acid sequence, so different bonding in the tertiary structure so the shape is different
Why is the region variable?
To form antigen antibody complexes
What are the two jobs of antibodies?
-agglutination and to mark the pathogen for the phagocyte
What is agglutination?
Brings antibodies and pathogens together so the phagocytes only have to go to 1 site
How does targeting medication with antibodies work?
They attach a therapeutic drug to an antibody - making use of how specific the antibody is to the antigen
For what disease does targeted medication with antibodies use?
Cancer - more effective than radiotherapy/chemotherapy because less surrounding cells are damaged
How do monoclonal antibodies stop the uncontrolled growth of cancer cells?
They attach to the receptors on their specific cancer cells which block the chemicals that stimulate the uncontrolled growth
What type of antibody does breast cancer use?
Herceptin monoclonal antibody - direct
What is three advantages of using direct antibody therapy?
1) non toxic
2) highly specific
3) fewer side effects
What does indirect antibody therapy involve?
Attaching a cytotoxic to the monoclonal antibody - when it attached to cancer cells it kills them
What are two advantages of using indirect antibody therapy?
1) can be used in smaller doses as targeted on specific sites
2) cheaper as small doses
Why are monoclonal antibodies good at diagnosing?
They have over 100 diagnostic products on them
Why are monoclonal antibodies used for diagnostic uses?
They produce a more rapid result
What disease are monoclonal antibodies used to diagnose?
Men with prostate cancer
What diseases produces unusually high levels of prostate specific antigen?
Prostate cancer
How do the monoclonal antibodies early diagnose prostate cancer?
The monoclonal antibody reacts with antigens and measures the level of them - too high of PSA would indicate prostate cancer
What hormone does the use of monoclonal antibodies in pregnancy tests rely on?
- human chorionic gonadatroptin (hCG) produced by the placenta
Which is present in pregnant women’s urine
How is the hCG-antibody-colour-complex formed?
The monoclonal antibodies are linked to coloured particles and the hCG binds to the antibody
